Growing Healthy Houseplants (Storey Basics, 2014) by Ellen Zachos is an essential guide for houseplant owners. Zachos discusses the basics of keeping plants, from choosing the right plants for your space and how to properly care for them. The following excerpt, from “Part Two: Daily Care,” offers easy-to-follow instructions for how to repot your favorite houseplants.
1. Find the Right Pot
First, choose a container one size bigger than your current pot. Pots come in standard sizes, usually in 2-inch increments. A 6-inch pot is a pot with an interior top diameter of 6 inches. The next size up would be an 8-inch pot, and that would give a 6-inch rootball a full inch of fresh soil all the way around.
Resist temptation to move your plant into a much bigger pot. You may think you’re saving yourself time because you won’t have to repot the plant so often if you move it into a big pot now, but over-potting can kill a plant. If you moved a 6-inch rootball into a 12-inch pot, that would give the rootball 3 inches of fresh soil all the way around.
Why would that be a bad thing? After you water a plant, the soil gradually dries out as the roots absorb water from the soil. This balance between wet and dry, oxygen and water, is crucial. Fresh soil with no roots in it will stay wet, surrounding the rootball with moisture, keeping the roots wet for longer than they should be. The roots may rot, killing the plant, slowly, in front of your very eyes.
2. Remove the Plant
Find a pot one size larger than your current container, and have a bag of potting mix and a pottery shard (a broken piece of an old pot) or small piece of landscape cloth or screen. Cover the hole in the bottom of the pot with one of the above to keep soil from dribbling out the bottom of the pot, then add an inch or two of soil. Next, knock the plant out of its pot.
To do this, tip the pot upside down, holding the stem of the plant loosely between your fingers. If the rootball doesn’t slip right out, knock the pot (hard) against the side of a table, or, if the pot is plastic, roll it on its side while pressing down hard. This should loosen the rootball so you can slide it out gently. It is not unheard of for a plant’s roots to attach themselves to the pot’s walls. You may need to crack a terra-cotta pot (try a hammer) and peel away the pieces. Or, for a plastic pot, cut it apart with a pair of scissors.
Take a look at the rootball once it’s exposed. An extremely overgrown plant may have roots that completely encircle the plant. If this is the case, poke your fingers in and among the roots with your fingers, teasing the roots apart to loosen them up. (Notice how little room there is for soil?) Use the same strength of touch you’d use to untangle a snarl in your hair: firm but kind.
3. Repot the Rootball
Place the rootball in the center of its new pot, holding it in place with one hand, then add soil around the edges with the other. Press the new soil in firmly (you may need to use a dowel or chopstick to really poke it down), adding more until the new soil meets the level of the existing soil. You always want to maintain the original potting level of the plant. This should be about 1/2 inch to 1 inch below the rim of the pot so water won’t splash out every time you water the plant.
4. Water Thoroughly
Bring the plant to the sink, and water it thoroughly. (I know you remember how to do this!) The soil may settle in a little while you’re watering. If necessary, add more, pressing it in firmly and watering again.
If your newly transplanted plant looks droopy or wilted, keep it in a shady spot for about a week, away from air conditioners, radiators, or fans. All three of these dry the air. After a week your plant should be perky again. You can move it back to its regular place and resume normal care.
Excerpted from Growing Healthy Houseplants (c) Ellen Zachos. Illustration by (c) Beverly Duncan. Used with permission of Storey Publishing.